3
Graph shows measured altitudes (blue) at different points on 7 th floor in CEPSR building and pressures at sea level (red) posted in the NOAA site Instead of location, weather seems to have a significant effect – Actual altitude change during 34 minutes: m – Expected altitude change due to the weather: m – Pressure increases from kPa to kPa during 2 hours => rate of altitude change is m/min

7
Discussion We do not observe any significant changes in barometer readings at different points on the same floor – We expected altitudes measured in restrooms would increase due to lower pressure, but they do not Instead, measured altitude changes as time goes or as weather changes However, we cannot conclude HVAC does not affect barometer readings – We don’t know the status and intensity of HVAC of the buildings

8
Related work “The main errors in indoor measurements were caused by the different ventilation in different rooms in building. However, no drastic changes in the air pressure were noticed.” - J. Parviainen, J. Kantola, and J. Collin, “Differential Barometry in Personal Navigation,” presented at the IEEE/ION Position Location and Navigation System (PLANS), “Before ignition in the PPV experiment, the fan created uniform pressures at all three elevations of 21 Pa (0.003 PSI).” - S. Kerber and W. Walton, “Effect of Positive Pressure Ventilation on a Room Fire,” U.S. Department of Commerce, NISTIR-7213, Mar = 1.74 m